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I've designed a circuit that I've already had tested it on breadboard and it has worked fine. When I did it on a PCB a new issue has appeared. The voltage regulator (I'm currently using a 7805) gives right values at no load, but when I attach the Atmega328 on it the output voltage goes to 1V instead of 5V and input goes to 2.5V, instead of 12V at no load. I've already tried to change the capacitors. As specified on DS, after rectify it I put a 330nF on INPUT and another of 100nF on OUTPUT, both ceramics. Can someone, please, figure out what's going on?

entire circuit

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  • \$\begingroup\$ if someone desire I can put a picture of the board \$\endgroup\$ Commented Feb 24, 2015 at 17:37
  • \$\begingroup\$ Also I've already tried it with 3 different LM7805 and got the same results. Tried without the 330nF cap since its really close to 470uF cap (used for filtering) and a 100uF instead of 100nF and got the same results. \$\endgroup\$ Commented Feb 24, 2015 at 17:39
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    \$\begingroup\$ Is anything getting hot? I would suspect a chip power is wired backwards. \$\endgroup\$ Commented Feb 24, 2015 at 18:08
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    \$\begingroup\$ Although nothing getting hot, maybe only the transformer, by a little, there was a flipped IC. Now the thing is really hot is my head. I think Eagle have trolled me. The atmega was horizontally mirrored. The schematic is correct, but the board doesn't match. I'll figure what happened after solve my problem. Thx you all... Like always, it's the small rocks that make you fall. \$\endgroup\$ Commented Feb 24, 2015 at 18:21
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    \$\begingroup\$ Somehow my Atmega was on top board instead of on bottom. Probably I messed with it when arranging the components and didn't realize it. ¬¬ \$\endgroup\$ Commented Feb 24, 2015 at 18:26

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This question has been solved. More details of what happened on comments:

Although nothing getting hot, maybe only the transformer, by a little, there was a flipped IC. Now the thing is really hot is my head. I think Eagle have trolled me. The atmega was horizontally mirrored. The schematic is correct, but the board doesn't match. I'll figure what happened after solve my problem. Thx you all... Like always, it's the small rocks that make you fall. –  Pedro Quadros 1 hour ago

Some how my Atmega was on top board instead of on bottom. Probably I messed with it when arranging the components and didn't realize it

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